A website that tricks unwary drivers into paying three times the cost of using the Dartford crossing has been removed from the top of Google search results, following pressure from the Observer.

Drivers crossing the Thames via the Queen Elizabeth II Bridge from Essex into Kent, or the Dartford tunnel in the other direction, see signs saying “Dart Charge find us online”. But they give no website address and, until we intervened, anyone doing a Google search for “Dartford crossing” saw an ad for Paydartfordcharge.co.uk at the top of the page.

Paydartfordcharge.co.uk and Paydartfordcrossingcharge.co.uk, identical sites run by Sarah Jones Trading from an address in Bristol, are “copycat” websites. They mimic that of a government department or official service, and mislead users into paying excessive prices for a service, often with no tangible benefit to the consumer.

Drivers using the Dartford crossings between 6am and 10pm have to pay £2.50 per trip, via the official website, gov.uk/pay-dartford-crossing-charge. But Paydartfordcharge.co.uk charges £7.50 per crossing. A disclaimer states that the site is not connected or affiliated to the official Dart Charge site and adds: “We charge a service fee for assisting you in the application and payment of the Dartford crossing charge.”

However, in some cases the site fails to pass on the drivers’ payments, and they incur penalty charges. Benjamin Jackson from Epsom, Surrey, ended up with fines totalling £75 after using Paydartfordcharge.co.uk.

“I now realise about the small print but it never crossed my mind someone could set up a fake site to con people,” he said. “I thought I was on the official site as I’d typed in ‘pay dart charge’. If they are going to take the mickey and charge three times the official crossing price, they should at least pass the money on. I’d never have known if my appeal for the fine hadn’t been rejected, and I’d have kept on using the site.”

A disclaimer should set alarm bells ringing – if it was clear it was a commercial site, it wouldn’t need a disclaimer

Mike Andrews, National Trading Standards

Copycat sites often pay to appear at the top of Google search results, or use tools to achieve a high level in the rankings. They appear above official sites in the results and have similar names, so consumers often mistake these revenue-generating sites with the real thing.

Google has now removed adverts for Paydartfordcharge.co.uk and Paydartfordcrossingcharge.co.uk, although the sites still exist. Sarah Jones Trading had not responded to the Observer’s request for comment at the time of publication.

Google spokesman Elijah Lawal said: “Because we want ads people see on Google to be useful and relevant, we have policies that exclude ads for paid products or services that are available from a public source for free or at a lower price, unless they offer a clear added value. If we find sites breaking this rule, we take appropriate action.”

But ridding the internet of copy-cat sites is like trying to herd cats – they pop up with alarming regularity. As well as toll roads, copycat sites target people wanting to renew a passport or driving licence, book a driving test, apply for an Ehic card or buy a fishing licence.

Mike Andrews of National Trading Standards’ eCrime Team says: “The key thing is, are consumers being misled into paying for something they wouldn’t have paid for if all the information had been presented in a clear and legible way? The presence of a disclaimer should set alarm bells ringing – if it was clear it was a commercial site, it wouldn’t need a disclaimer.”

Consumers concerned about misleading ads on Google can submit complaints to its AdWords site.